Prior art biological tissue cutting handpieces, e.g., as currently available on the market, are either pneumatic or electric. Both types of such biological tissue cutting handpieces have a single port and fixed size, and typically allow only one stroke length. Spring return pneumatic handpieces have a variable duty cycle, which is reduced as speed is increased. Dual line pneumatics handpieces currently operate at a constant duty cycle and do not have adjustable port apertures. Neither of these types of biological tissue cutting handpieces allows for a selectable stroke.
Some prior art techniques have endeavored to vary the size of the port aperture, but most of these prior art techniques have varied the port with cut speed. This is essentially an extension of prior art pneumatic drive techniques/apparatus, where the duty cycle (the percentage of time the port is open) reduces as cut speed increases leading to a point where the cutter is no longer allowed to completely open. Other prior art techniques address port configurations with manual adjustments.
While such prior art techniques may be suitable for their respective intended purposes, there exists a need for techniques that provide improved adjustability of handpiece performance characteristics.